The hippopotamus (/ˌhɪpəˈpɒtəməs/ HIP-ə-POT-ə-məs; pl: hippopotamuses or hippopotami; Hippopotamus amphibius), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two extant species in the family Hippopotamidae, the other being the pygmy hippopotamus (Choeropsis liberiensis or Hexaprotodon liberiensis). Its name comes from the ancient Greek for 'river horse' (ἱπποπόταμος). Aside from elephants and rhinos, the hippopotamus is the largest land mammal. It is also the largest extant land artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, the closest living relatives of the hippopotamids are cetaceans (whales, dolphins, porpoises, etc.), from which they diverged about 55 million years ago. Hippos are recognisable for their barrel-shaped torsos, wide-opening mouths with large canine tusks, nearly hairless bodies, pillar-like legs, and large size: adults average 1,500 kg (3,310 lb) for bulls (males) and 1,300 kg (2,870 lb) for cows (females). Despite its stocky shape and short legs, it is capable of running 30 km/h (19 mph) over short distances. (Source: Wikipedia.org, CC BY-SA)